Apparatus and method for removing fluids from a well

Abstract

Apparatus and method for removing fluid from a well. The apparatus is mobile, and includes a power winch mounted on a mobile support means with a cable attached to the winch. A constant tension maintaining unit is connected to the winch to maintain relatively constant tension on the cable while the cable is wound off the power winch into the well, and a swab is mounted on the free end of the cable. The swab is operable to lift the fluid out of the well when the cable is wound back onto the power winch. Also included is a means in fluid connection with the well operable to receive the fluid lifted out of the well by the swab. Also provided is a swab bar for use in removing fluid from a well and a device for effecting a seal with the well head.

What is claimed is: 
     
       1. An apparatus for removing fluid from a well comprising: mobile support means;   a power winch mounted on said mobile support means having a cable attached thereto;   means operably connected to said power winch for maintaining relatively constant tension on said cable while said cable is wound off said power winch into a well;   a swab mounted on the free end of said cable for lifting fluid out of the well when said cable is wound back onto said power winch;   means in fluid connection with the well for receiving the fluid lifted out of the well by said swab.   
     
     
       2. The apparatus in claim 1 wherein said tension maintaining means comprises: means for braking said power winch;   a brake control valve; and   cable slack detection means for shifting said brake control valve from a first position to a second position, said second position being operable to apply said braking means to said power winch.   
     
     
       3. The apparatus of claim 2 wherein said cable slack detection means comprises a pulley riding on said cable, a control cable attached to said pulley, and a weight attached to said control cable. 
     
     
       4. The apparatus of claim 3 wherein said brake control valve is releasably clamped to said control cable. 
     
     
       5. The apparatus of claim 2 wherein said power winch braking means comprises a brake band which may be releasably applied to a drum which is integral with the reel of said power winch. 
     
     
       6. The apparatus of claim 5 wherein said power winch braking means additionally comprises a lever attached to said brake band at one end and having a weight suspended from the other end, and a hydraulic cylinder counteracting the downward force applied to said lever by said weight such that, when the hydraulic pressure to said cylinder is shut off, said weight causes said brake band to be applied to said brake drum. 
     
     
       7. The apparatus of claim 1 wherein said swab comprises a mandrel having a swab cup mounted thereon and a weight bar for causing said swab to sink down through the fluid in the well. 
     
     
       8. The apparatus of claim 7 wherein the mandrel of said swab is provided with an orifice through which fluid in the well passes as said swab moves downwardly in the well as said cable is wound off said power winch. 
     
     
       9. The apparatus of claim 8 wherein said orifice is provided with a valve for preventing the passage of fluid therethrough when said swab moves upwardly in the well as said cable is wound onto said winch. 
     
     
       10. The apparatus of claim 8 wherein said mandrel is provided with an insert and said orifice is located in said insert, said insert being releasably mounted on said mandrel. 
     
     
       11. An apparatus for removing oil from a well comprising: mobile support means;   a reel mounted on said mobile support means;   a cable stored on said reel and having one end attached thereto;   a swab attached to the free end of said cable and having an integral weight for causing said swab to sink down through the oil in an oil well;   a motor for rotating said reel to lower and to retract said cable and said swab;   means connected to said reel and said cable for maintaining constant tension on said cable comprising a brake,   a brake control valve, and   cable slack detection means for shifting said brake control valve between a first and a second position, said brake control valve being operable in said first position to stop the rotation of said reel and to allow said motor to rotate said reel in said second position, allowing said cable to play out and down into the oil well; and     means for receiving and storing the oil removed from the well when said cable is retracted by said reel.   
     
     
       12. An apparatus for maintaining relatively constant tension on a cable used to lower a weight through a fluid comprising: a reel for storing a cable;   a cable attached to said reel;   a weight attached to the free end of said cable;   a drum integral with said reel;   a brake band encircling said drum and having a tension rod integral therewith, said tension rod being pivotally mounted to one end of a lever arm;   a first weight suspended from the other end of said lever arm;   means for overcoming the downward force applied to the end of said lever arm by said first weight, thereby preventing the application of force to said tension rod and the engagement of said drum by said brake band;   a pulley riding on said cable;   a second weight attached to said pulley operable to pull said pulley downwardly when said cable loses tension; and   means for transmitting the downward movement of said pulley to said means for overcoming the downward force of said first weight operable to cause said means for overcoming the downward force of said first weight to cease overcoming the downward force of said first weight, thereby causing said brake band to engage said drum to stop the rotation of said reel.   
     
     
       13. A method of removing fluid from a well comprising: lowering a swab on the end of a cable down into the fluid of said wells;   maintaining relatively constant tension on said cable by decreasing the rate at which said swab is lowered to compensate for the buoyancy of said swab once said swab reaches the fluid in said well;   effecting a seal between said swab and the walls of the well;   pulling said swab out of the well by retracting said cable; and   collecting the fluid lifted out of said well by said swab.   
     
     
       14. The method of claim 13 wherein said swab is lowered through the fluid in said well by allowing the fluid to pass through an orifice in said swab. 
     
     
       15. The method of claim 14 further comprising closing said orifice when said cable is retracted. 
     
     
       16. The method of claim 14 wherein the rate at which said swab is lowered through the fluid in said well is changed by changing the diameter of the orifice in said swab. 
     
     
       17. A swab bar for use in removing fluid from a well comprising: a mandrel;   means on said mandrel for retaining a swab cup around the circumference thereof;   means in said mandrel for allowing the passage of fluid therethrough as said mandrel is lowered down through the fluid in a well; and   means in said fluid passing means for controlling the rate at which said mandrel is lowered through the fluid.   
     
     
       18. The swab bar of claim 17 wherein said fluid passing means comprises an orifice through said mandrel. 
     
     
       19. The swab bar of claim 18 wherein said mandrel is provided with an insert having said orifice located therein, said insert being releasably mounted in said mandrel whereby the rate at which said mandrel is lowered through the fluid is changed by mounting an insert in said mandrel with an orifice of different diameter. 
     
     
       20. The swab bar of claim 17 wherein said swab cup is retained on said mandrel by a flange on said mandrel. 
     
     
       21. The swab bar of claim 20 additionally comprises a weight wherein said mandrel threadably engages said weight and said swab cup is retained on said mandrel between said flange and said weight. 
     
     
       22. The swab bar of claim 17 wherein said swab cup is retained on said mandrel by a shear sleeve, said shear sleeve being releasably retained on said mandrel. 
     
     
       23. The swab bar of claim 22 wherein said shear sleeve is retained on said mandrel by frangible means.